Demystifying G1GC
summary
G1GC targets short pauses by letting you set a 200ms pause target (via the max-pause flag) and by splitting the heap into regions sized 1–32MB so it adapts on the fly to about ~2000 regions. It performs young, concurrent mark, and mixed collections; humongous objects (>½ region) go straight to old gen and can trigger long evacuation stalls. Use PrintGCDetails and PrintGCApplicationStoppedTime plus tools GCViewer or JClarity to inspect logs; evacuation failures have caused pauses measured up to 95 seconds.
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chapters (12)
- 0:00Intro
- 1:00Why G1GC
- 5:05How does it work
- 6:10What is completely new
- 7:40Garbage collection
- 14:35Log analysis
- 15:41Log recommendations
- 19:46Heap Size
- 21:10Mongoose allocations
- 23:36Evacuation
- 26:03Avoiding evacuation
- 29:19Duplicate strings
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